The problem is your "once in a blue moon." This can easily read as, "arbitrary time where we don't have any other justification for kicking out someone we dislike."
For the truly terrible people, you really shouldn't need a code of conduct to kick them out. An assumption of good behavior is a decent assumption. For abrasive people that you don't want to deal with, things get harder if they are just difficult in good faith. But, the difficult in good faith people are the most difficult to work with using a code of conduct. Being in good faith, they likely literally don't see the problems they cause. And the code does nothing to educate.
> For the truly terrible people, you really shouldn't need a code of conduct to kick them out.
Good point, often overlooked. Though I hear the creak of an opening door to "we just don't like you" culture-fitting exclusion.
Written policies separate, by both time and person, rule creation from rule enforcement. That disconnect gives both the policymakers and enforcers CYA protection:
The rule I wrote wasn't intended to be used this way.
If it were up to me… but it's not, I just follow the rules.
Written policies are just another way to creak that door into a culture-fitting exclusion. Often done much more heavy handedly, as that second hypothetical line of yours is as often a lie.
I get the desire to make things more objective, but as long as people are involved, it is going to be near impossible to separate that aspect from things without trouncing on people that are otherwise invisible to the ones writing the rules.
For the truly terrible people, you really shouldn't need a code of conduct to kick them out. An assumption of good behavior is a decent assumption. For abrasive people that you don't want to deal with, things get harder if they are just difficult in good faith. But, the difficult in good faith people are the most difficult to work with using a code of conduct. Being in good faith, they likely literally don't see the problems they cause. And the code does nothing to educate.